This application is being submitted to request partial funding support for the Twelfth International CEA Symposium, to be held July 29- August 1, 2001 in Providence, Rhode Island. This symposium brings together clinical and basic scientists from all parts of the world to discuss the latest research on the carcinoembryonic antigen (CEA) family of immunoglobulin-like cell adhesion molecules. During the past eleven years of this Symposium, much has been learned about the structural and functional characteristics of this large family o proteins. Particularly intriguing is the role CEA family members play in carcinogenesis, which is currently the topic of intense investigation. Although the molecular pathways involved are just beginning to be understood, there is strong evidence showing that both the phospholipid linked (CEA) and transmembrane (CEACAM I ) members of this family are multifunctional signal transducing proteins, with important roles in development and maintenance of normal tissue architecture. Loss of CEACAM I a is seen in a high percentage of carcinomas in the colon, prostate and liver, and re-introduction of the protein into tumor cell lines has been shown to suppress tumorigenesis. In addition, CEACAMla acts as the surface receptor for pathogenic Neisseria, and H. influenzae, an area of growing interest because of its potential for providing new methods for disease intervention. In the past three years this conference has been held in Europe, and a return to the US will facilitate participation by North American investigators. The current conference will focus on recent developments in the cellular and molecular biology of CEA family members, and explore the role o CEACAMla in signal transduction and tumorigenesis. The scientific program will include seminars by established leaders in the field, and a poster session based on submitted abstracts will be held to facilitate less formal discussions. Established researchers as well as young investigators and students are expected to attend, and women and minorities are encouraged to participate. The relatively small size of the Symposium insures ample opportunities for networking and development of productive new research interactions.